From f395dcae7a68497751869cf0031fd8ce5e115f0a Mon Sep 17 00:00:00 2001 From: Jiang Liu Date: Wed, 27 Aug 2014 13:53:11 +0800 Subject: [PATCH] x86: irq: Fix bug in setting IOAPIC pin attributes Commit 15a3c7cc9154321fc3 "x86, irq: Introduce two helper functions to support irqdomain map operation" breaks LPSS ACPI enumerated devices. On startup, IOAPIC driver preallocates IRQ descriptors and programs IOAPIC pins with default level and polarity attributes for all legacy IRQs. Later legacy IRQ users may fail to set IOAPIC pin attributes if the requested attributes conflicts with the default IOAPIC pin attributes. So change mp_irqdomain_map() to allow the first legacy IRQ user to reprogram IOAPIC pin with different attributes. Reported-and-tested-by: Mika Westerberg Signed-off-by: Jiang Liu Cc: Konrad Rzeszutek Wilk Cc: Tony Luck Cc: Joerg Roedel Cc: Greg Kroah-Hartman Cc: Benjamin Herrenschmidt Cc: Rafael J. Wysocki Cc: Bjorn Helgaas Cc: Randy Dunlap Cc: Yinghai Lu Cc: Borislav Petkov Cc: Grant Likely Cc: Prarit Bhargava Link: http://lkml.kernel.org/r/1409118795-17046-1-git-send-email-jiang.liu@linux.intel.com Signed-off-by: Thomas Gleixner --- arch/x86/kernel/apic/io_apic.c | 15 ++++++++++++++- 1 file changed, 14 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/apic/io_apic.c b/arch/x86/kernel/apic/io_apic.c index 29290f554e79..40a4aa3f4061 100644 --- a/arch/x86/kernel/apic/io_apic.c +++ b/arch/x86/kernel/apic/io_apic.c @@ -1070,6 +1070,11 @@ static int mp_map_pin_to_irq(u32 gsi, int idx, int ioapic, int pin, } if (flags & IOAPIC_MAP_ALLOC) { + /* special handling for legacy IRQs */ + if (irq < nr_legacy_irqs() && info->count == 1 && + mp_irqdomain_map(domain, irq, pin) != 0) + irq = -1; + if (irq > 0) info->count++; else if (info->count == 0) @@ -3896,7 +3901,15 @@ int mp_irqdomain_map(struct irq_domain *domain, unsigned int virq, info->polarity = 1; } info->node = NUMA_NO_NODE; - info->set = 1; + + /* + * setup_IO_APIC_irqs() programs all legacy IRQs with default + * trigger and polarity attributes. Don't set the flag for that + * case so the first legacy IRQ user could reprogram the pin + * with real trigger and polarity attributes. + */ + if (virq >= nr_legacy_irqs() || info->count) + info->set = 1; } set_io_apic_irq_attr(&attr, ioapic, hwirq, info->trigger, info->polarity); -- 2.20.1